1. Field of the Invention
The present invention relates to an image reading device provided with an automatic document feeding means, and a function for reading and combining a plurality of partial images.
2. Description of the Related Art
Japanese Unexamined Patent Application No. HEI 3-210873 discloses an image reading device for reading partial areas by reading a partial area of a large-size document, comparing the partial image data of said partial area with the partial image data of another partial area of another previously read partial area of said large-size document, and determining whether or not the two partial image data have an overlapping area via pattern matching, so as to set conditions of overlapping areas.
Japanese Unexamined Patent Application No. HEI 3-222573 discloses a device for reading and combining a plurality of partial images.
Japanese Unexamined Patent Application No. HEI 3-210873 discloses a device wherein overlapping areas of the aforesaid partial area and the aforesaid other partial area are readily avoided because the relative position of the reading device relative to said partial area of a document is determined by an operation performed by an operator. In this instance, the operation is complicated by the necessity of once again performing position determination. Furthermore, a relative dislocation of overlapping areas occurs due to the position determining operation even when positioning can be determined so as to produce an overlap area; this situation complicates the pattern matching process, consumes much time, and readily generates errors.
In the device disclosed in Japanese Unexamined Patent Application No. HEI 3-222573, pattern matching by overlap areas cannot be accomplished naturally because each partial image does not have an overlap area. therefore, dislocation is readily generated at the boundary regions of adjacent partial images.